Copyright © 2006-2007 Network for sustainable use of energy in water and wastewater systems
The topic has been sub-divided into the following themes:–
To test drive the biogas fuelled Volkswagon Caddy Van contact John Baldwin at:
CNG Services Ltd
Rowanleigh
37 St Bernards Road
Olton
Solihull B92 7AX
0121 707 8581
johnbaldwin@cngservices.co.uk
www.cngservices.co.uk
These subdivisions have been made purely for clarity and to make it easier to navigate through the section. The divisions are not definitive, for example, information on gas cleaning can be found within documents cited under transport fuel and also power generation and CHP.
Much of the material presented here does not relate specifically to biogas derived from sewage sludge, but the technologies employed for gas cleaning and energy conversion are common to all biogas, regardless of the feedstock.
The European Union has supported a large number of projects looking at biogas for energy and some of these are listed under the relevant theme such as transport fuel or fuel cells, etc.
A limited number of technical journal papers are listed, although they need to be purchased from the relevant publisher. This is just to give a flavor of the type of material that is available. Searches of publisher's websites and databases will yield a large number of specialist papers. Relevant websites include Elsevier, ScienceDirect, Swetwise, and Wiley Interscience.
In no way does this section attempt to be comprehensive. Much additional material can be found by following the links in the web sites cited. The objective is rather to provide an overview of the topics and activities relevant to biogas use for energy.
The Biogas Barmmeter provides a summary of biogas production and use across the EU in 2005 and 2006. The 11 page report published by EuObserv'ER in May 2007 also provides several case study summaries of developments in key EU countries. The Biogas barometer is published annually.
IEA Tasks develop three year rolling programmes of work for each topic area. Task activities change and end as work proceeds and technology develops. This website contains a list of technology suppliers and a considerable number of publications. It also hosts the IEA Bio-energy Biogas Industry Forum. The Forum is open for anyone who wants to contribute with information and knowledge about biogas equipment and biogas technology.
The purpose of the SGC is to co-ordinate Swedish industrial interest in R&D concerning gas fuel technology. This is done on a "non profit"-basis. The Swedish government represented by Swedish Energy Agency participates in financing the R&D-program. SGC was established in 1990 and is owned by E.ON Gas Sverige AB, E.ON Sverige AB, Göteborg Energi AB, Lunds Energi AB, Öresundskraft AB and The Swedish Gas Association.
The website contains a considerable number of technical and semi-technical reports and articles, many of which are available in English.
Publication Date: March 2008 | File Size: Weblink
The Power point presentations from the Nordic Biogas Conference held in Malmo, Sweden can be viewed at this weblink.
Publication Date: 2003
Executive summary (11p) 60kb Download >
Chapters 1-5 (68p) 1.24MB Download >
Chapters 6-end (47p) 735kb Download >
Publication Date: 2006 | File Size: 11p, 1.36MB
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This document summarises basic data on biogas production and use in Sweden. The data relates to 2006 but has been updated in places with 2007 data when translated into English.
Publication Date: 2007 | File Size: 161p, 2.72MB
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This workshop and study tour was hosted by the University of Southern Denmark between 14th & 16th June of this year. The full range of biogas topics were covered during the event.
Publication Date: 2006 | File Size: 4p
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Biogas production is a very promising option to generate renewable energy. Currently, specific parameters on the anaerobic digestibility of animal manures are unavailable which restricts the exploitation of the promising potentials. Manures received from contrasting dairy systems were anaerobically digested. The resulting methane yield ranged between 125 and 166 Nl CH4 (kg VS)- 1 depending on the milk yield and diet of the dairy cow. A 6% supplementation of glycerine to pig manure and maize silage resulted in a significant increase in CH4 production from 569 to 679 Nl CH4 (kg VS)- 1.
A paper available for purchase from ScienceDirect.
Publication Date: August 2006 | File Size: 6p, 158KB
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Hydrogen and methane were produced from wastewater sludge using a clostridium strain. The original sludge and pre-treated (acidified, basified and freeze/thawed) sludge's were the tested samples. Some pre-treatments enhanced hydrogen yield, whereas other treatments enhanced methane yield. Hydrogen fermentation can be used as a pre-stage to improve subsequent methane production from wastewater sludge.
Publication Date: 2002 | File Size: 10p, 100KB
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The IWA Anaerobic Digestion Modeling Task Group was established in 1997 at the 8th World Congress on Anaerobic Digestion (Sendai, Japan) with the goal of developing a generalised anaerobic digestion model. The structured model includes multiple steps describing biochemical as well as physicochemical processes. The biochemical steps include disintegration from homogeneous particulates to carbohydrates, proteins and lipids; extra cellular hydrolysis of these particulate substrates to sugars, amino acids, and long chain fatty acids (LCFA), respectively; acidogenesis from sugars and amino acids to volatile fatty acids (VFAs) and hydrogen; acetogenesis of LCFA and VFAs to acetate; and separate methanogenesis steps from acetate and hydrogen/CO2. The physico-chemical equations describe ion association and dissociation, and gas-liquid transfer. Implemented as a differential and algebraic equation (DAE) set, there are 26 dynamic state concentration variables, and 8 implicit algebraic variables per reactor vessel or element. Implemented as differential equations (DE) only, there are 32 dynamic concentration state variables.
Publication Date: 1999 | File Size: 14p, 5.88MB
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Anaerobic digesters often exhibit significant stability problems, that may be avoided only through appropriate control strategies. Such strategies require, in general, the development of appropriate mathematical models, which adequately portray the key processes that take place. This paper reviews the current state of the art in anaerobic digestion modeling, and identifies the key areas that require further research endeavors.
The terms biogas cleaning and upgrading are often used interchangeably. However, upgrading tends more accurately to refer to action to increase the suitability of biogas for the more demanding uses of transport fuel and the gas grid. Biogas contains a range of impurities including hydrogen sulphide, siloxanes (depending on feed stock), water, and particulates. These impact on power generating equipment, degrading equipment and reducing efficiency. The more sophisticated the technology, the greater the gas cleaning required to ensure its satisfactory operation, Diesel engines are more tolerant of impurities than are gas turbines, which in turn can tolerate a poorer quality gas than can fuel cells. There is increasing interest in the supply of biogas to natural grid network and this requires very high level gas cleaning, notably carbon dioxide removal, if the biogas is to match the quality of natural gas. The same applies when biogas is to be used for vehicles.
Publication Date: | File Size: 6p, 509KB
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A Dutch government document describing several different proprietary systems for biogas cleaning, their suitability for different purposes and the Dutch companies that provide them.
Publication Date: 2000 | File Size: 20p, 1MB
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An IEA Bio-energy document describing cleaning technologies for different impurities.
Publication Date: December 2006 | File Size: 19p, 384KB
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This report, produced under the auspices of the IEA Bio-energy Task 37 Energy from Biogas and Landfill Gas, describes biogas use for heat and CHP, and within grid networks. Its also considers the methods and costs of gas cleaning and provides five case studies for grid injection and vehicle use.
Biogas can be used in both heavy and light duty vehicles. In Sweden, there are several local bus fleets where the major part of the urban public transport is operated on biogas. Biogas fuelled vehicles can reduce CO2 emissions by between 75% and 200% compared with fossil fuels, and air quality is improved due to virtually zero particulate emissions.
Biogas for vehicle use can be produced in the UK at a cost of between 50-60p/kg (including duty but not VAT). This is comparable with the current price of compressed natural gas at around 55p/kg. However, although this makes biogas about 40% cheaper than diesel and 55% cheaper than petrol, high capital costs make it less attractive. It costs around £25,000 to convert a heavy duty vehicle and £5,000 to convert a light duty vehicle. The UK produces around 30 million dry tones of this waste material per year, which could, theoretically meet around 16% of transport fuel demand.
Publication Date: March 2007 | File Size: 4p, 217KB
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Biogas has been used as vehicle fuel since the beginning of the '90´s in Sweden. To date, there are 30 upgrading plants in operation or under construction and over 11,500 vehicles that use methane fuel. Biogas is used in large scale systems and in several cities like Kristianstad and Linköping all of the city buses run on biogas. The market for biogas as vehicle fuel is growing in Sweden and the sales increased with almost 50 % 2006 compared with 2005. This document reviews the use of biogas for transport in Sweden today.
Publication Date: June 2006 | File Size: 52p, 1.2MB
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This report from the National Society for Clean Air and Environmental Protection (NSCA) sets out the resource that is available for producing biogas, together with the basic details of production technology and estimates the theoretical maximum amount of gas that could be produced in the UK. It goes on to explore how this gas can be used in vehicles, describing the basic technology requirements, vehicle availability and fuel supply issues. The energy and emissions data on biogas as a transport fuel are analysed, and the costs of producing and using the fuel are also estimated.
Trollhätten http://www.energie-cites.org/db/trollhattan_569_en.pdf
Linköping http://www.energie-cites.org/db/linkoping_113_en.pdf
BioGasMax http://www.biogasmax.eu/
The European Biogasmax project has created a network of biogas-related demonstrations in six European cities or regions with the aim of sharing experiences of best practices in managing urban transport using biogas fuel.
The research and development projects carried out in the context of BIOGASMAX are closely tied to the following four main fields of technological activities:
Feedstocks utilised within the project include sewage sludge, agricultural wastes, food processing wastes, landfill gas and putrescible MSW.
One output from the network will be the Biomethane Decision Guide, which will explain all aspects surrounding the biomethane decision - from the biomethane pathway to biomethane business - illustrated by practical examples.
View the BioGasMax website for case studies from:
Göteburg http://www.biogasmax.eu/goteborg/previous-experience/
Lille http://www.biogasmax.eu/lille/previous-experience/
Stockholm http://www.biogasmax.eu/stockholm/previous-experience/
Berne http://www.biogasmax.eu/berne/previous-experience/
Encounter CLEAN BUSES
Learn more about biogas fuels vehicles - 24th & 25th September 2007, Lille France. This will be an occasion to make a complete assessment of the progress made in the various sectors for buses since 2004: NGV, LPG, diester, diesel with particulate filters and the DeNOx (SCR, EGR) system.
The European Biogas Max and Starbus projects will be discussed, in particular the European version of the SIMULIBUS calculator, which enables each system to assess its future (10 years) operating costs through estimates of equipment (PFs) or renewal of the vehicle park and to make economic, energy and environmental comparisons of sectors.
Bus makers and energy suppliers will discuss developments in what's on offer. View more information here http://www.biogasmax.eu/205-6th-study-days-encounter-clean-buses.html
FLEXIFUEL http://websrv5.sdu.dk/bio/flexfuel_sum.htm
The FLEXFUEL project aims to demonstrate that organic waste, sludge from wastewater treatment plants, animal manure and energy crops may be converted to ethanol and biogas for motor fuel. The treatment plant employed can produce ethanol at the same price as upgraded biogas. The project will :
The treatment plant producing biogas/bioethanol for Aeroe will have a net production of 20 GWh annually and treat more than 70,000 tons of waste, manure and green crops.Once fully operational it will replacement more than 20% of the petrol consumption in Ærø with ethanol
AGROPTI-GAS http://www.agroptigas.com/home/index.asp?sid=1635&mid=1
This EU project was completed in June 2006. It demonstrated the co-digestion of a ley crop and source separated putrescible household waste, the combination of the biogas produced, with that from the local sewage treatment plant, and the subsequent upgrading of the gas for use in buses and private cars.
Project final summary report
http://www.agroptigas.com/common/load_ext_file.asp?Source=ext_pages&Id=119408
Final technical report July 2006, 14.6MB
http://www.agroptigas.com/home/page.asp?sid=1635&mid=2&PageId=29378
Final report on digestion performance, July 2006, 445kb
http://www.agroptigas.com/home/page.asp?sid=1635&mid=2&PageId=29379
Other project reports can be viewed here (Read more):
http://www.agroptigas.com/home/page.asp?sid=1635&mid=2&PageId=29379
CHP plants in Denmark:
Hernin, http://www.energie-cites.org/db/herning_139_en.pdf
Aalborg http://www.energie-cites.org/db/aalborg_139_en.pdf
PROBIOGAS http://websrv4.sdu.dk/bio/probiogas.htm
Promotion of Biogas for Electricity and Heat Production in EU Countries - economic and environmental benefits of biogas from centralised co-digestion. This project ran from January 2005 to June 2007
A fuel cell consists of two electrodes sandwiched around an electrolyte. Oxygen passes over one electrode and hydrogen over the other, generating electricity, water and heat. Hydrogen fuel is fed into the "anode" of the fuel cell. Oxygen (or air) enters the fuel cell through the cathode. Encouraged by a catalyst, the hydrogen atom splits into a proton and an electron, which take different paths to the cathode. The proton passes through the electrolyte. The electrons create a separate current that can be utilized before they return to the cathode, to be reunited with the hydrogen and oxygen in a molecule of water.
A fuel cell system which includes a "fuel reformer" can utilise the hydrogen from any hydrocarbon fuel - from natural gas to methanol, and petrol. Since they rely on chemistry and not combustion, emissions from this type of a system would still be much smaller than emissions from the cleanest fuel combustion process.
There are many different types of fuel cell, brief descriptions of which can be found here http://www.fuelcells.org/basics/types.html. Fuel cells may be used both in stantionary applications and in transport.
Fuel cells have a number of benefits over diesel and gas turbine gensets including:
However, they are highly sensitive to impurities and biogas upgrading is a must if it is to be used in a fuel cell.
Publication Date: 2005 | Pages: 12 | File Size: 246KB
The use of biogas in fuel cells advantageously combines a cost effective renewable energy source with a technology which promises high electrical efficiency and low environmental impact. For the first time, the suitability of biogas as a fuel for proton exchange membrane fuel cell systems (PEMFC) has been experimentally confirmed. The advantages of this particular type of fuel cell are its low operating temperatures, modular system design and moderate costs. Measurement results from a 650 Wel test plant show a cell efficiency of 58% at a power density of 0.14 W/cm2. A particularly problematic component is the steam reformer with a thermal energy efficiency of 38%. A model calculation on the basis of an optimised PEMFC system shows that an electrical efficiency of over 40% can be obtained.
Publication Date: 2001
This article from Renewable Energy World provides an introduction to fuel cells and describes how biogas can be employed within them.
Publication Date: 2005
In the past years, research in the molten carbonate fuel cells (MCFC) area has been focusing its efforts on the utilisation of natural gas as fuel (S. Geitmann, Wasserstoff- & Brennstoffzellen-Projekte, 2002, ISBN 3-8311-3280-1). In order to increase the advantages of this technology, an international consortium has worked on the utilisation of biogas as fuel in MCFC. During the 4 years lasting RTD project EFFECTIVE two different gas upgrading systems have been developed and constructed together with two mobile MCFC test beds which were operated at different locations for approximately 2.000-5.000 h in each run with biogas from different origins and quality. The large variety of test locations has enabled to gather a large database for assessing the effect of the different biogas qualities on the complete system consisting of the upgrading and the fuel cell systems. The findings are challenging. This article also aims at giving an overview of the advantages of using biogas as fuel for fuel cells.
Publication Date: 2000
A short on-line paper from the Energy Systems Research Unit and Strathclyde University
Publication Date: 2000 | File Size: 2p, 254KB
A short paper from ChemComm describing how substantially reduced NOx emissions are obtained in the low temperature catalytic combustion of NH3-bearing simulated biogas by use of a novel 1%Pt/20%CuO/Al2O3-trapping catalyst and cyclic operation between fuel lean and rich conditions.
Columbia Boulevard WWTP in Portland is the largest wastewater treatment plant in Oregon. The facility handles approximately 82 million gallons of wastewater per day. A fuel cell at the plant uses the biogas from sludge digestions to generate electricity. The Columbia Boulevard fuel cell is the first installation in the western United States of a fuel cell running on wastewater digester gas and only the third such system in the USA.
Gas cleaning is necessary to eliminate impurities in the biogas. These are principally hydrogen sulfide, halogens (fluorine, chlorine and bromine), moisture, bacteria and solids. Biogas also contains carbon dioxide, which cannot be removed easily. The gas-cleaning system at Columbia Boulevard uses a potassium hydroxide impregnated activated carbon filter to remove the hydrogen sulfide. Once the biogas is cleaned it then enters the fuel cell where a processor extracts hydrogen from the gas. The fuel cell's power section then combines hydrogen and oxygen to produce water and electricity. A converter changes the direct current output from the power section into alternating current prior to it being fed into the local power grid.
The fuel cell at Columbia Boulevard is a phosphoric acid fuel cell manufactured by ONSI Corporation. Columbia Boulevard sells the power to Portland General Electric. The estimated electrical output of the fuel cell is about 170 kilowatts. The system will generate an estimated 1,400,000 kilowatt-hours a year. By producing its own electric power from the fuel cell, Portland expects to save over $60,000 a year in energy costs. A 200-kilowatt fuel cell would offset an estimated 736 tons of carbon dioxide emissions annually.
The City of Portland received financial support for the fuel cell from The Oregon Department of Energy, Portland General Electric and the Fuel Cell Climate Change Program. Support from the Oregon Department of Energy included tax credit through the Business Energy Tax Credit Program. The Oregon Bioenergy Program provided funds to help pay for engineering and design services for the gas-cleaning section of the fuel cell system. The total cost of the system was about $1.3 million.
AMONCO http://www.energyagency.at/projekte/biogas_fuelcell.htm
This EU project, now completed, had the following objectives:
Outputs from the project can be viewed here http://www.energyagency.at/projekte/biogas_fuelcell.htm#eva-publ
BIOSOFC http://www.biosofc.info/project.php
The EU LIFE project is designing and demonstrating 4 CHP Plants using two 5 kW Solid Oxide Fuel Cells (SOFC) working with landfill gas and biogas from anaerobic digestion. The project is on-going.
This section provides a short list of companies active in the biogas sector. Many more can be found in the material provided in previous sections, particularly the IEA Task 37 website and on the websites of many of the EU projects. Please note that the inclusion of a company in this list of equipment suppliers and consultancies does not constitute a recommendation of their products or services by EnerNet.
ÖKOBit
System planning and design, turn key suppliers, construction and maintenance and operation services.
http://www.oekobit.com/eng/index.html
DEUTZ Power Systems
Engineering company providing gas Genset and diesel Genset, offering services for a range of biomass produced biogases, including sewage gas and landfill gas
http://www.deutzpowersystems.com/Webgate/PowerSystems.nsf/FrameByKey/PFAL-6DSFPJ-DE-p
Scandinavian Biogas
Scandinavian Biogas specialises in optimizing the yield of biogas from stillage, glycerol and other organic matter. It offers technologies to upgrade biogas to biomethane for transport use as well as for co-digestion and sewage wastewater digestion.
http://www.scandinavianbiogas.se/DynPage.aspx?id=43550&mn1=2181
Apollo Environmental Systems Corp
Provide hydrogen sulphide scrubbers for biogas from municipal, industrial and agricutural sources.
http://www.apollo-environmental.com/index.html
Bioprocess Control
Bioprocess control specialise in supervisory and control application systems which optimise biogas production. Biogas OptimizerTM provides commercial biogas producers with a system for on-line monitoring and intelligent supervisory control of biogas digesters. The system has the ability to protect a biogas production process from overload, while allowing the maximum utilisation of digester capacity
http://www.bioprocesscontrol.com/